Instrument Air is a support gas with a standard pressure is 160-185 psig. System labeling must include whatever the normal pressure is if different than the designated standard pressure. (i.e. outlets, zone valves, all other shut offs, piping must include "x psig")

NFPA 99, 2018

5.1.13.3.4.5 Instrument air compressors shall be permitted to be of any type capable of the output pressure needed for the intended line pressure see Table 5.1.11, and of providing air meeting the definition of instrument air in 5.1.13.3.4.1.

Can you use non-instrument air (such as a filtered, dry, 60 psi compressed air system) for boom brakes and avoid the requirement for zone valves & area alarms?

5.1.6.11 The installation of manufactured assemblies shall be

tested in accordance with 5.1.12

I can't think of anything in 5.1.12 that specifically would prohibit this, and as long as the manufacturer instructions do not specifically say "Nitrogen or Instrument Air per NFPA 99" or something like that it would be fine

If the equipment manufacturer doesn't specify, what can control air(non-instrument air) notbe used for?

If we are using NFPA 99 as a guide I would say control air / non-instrument air can be used for anything that doesn't fall under the umbrella of medical support gas or medical air.

Having said that I might need to walk back what I previously wrote regarding what type of air sources can drive booms. Under the definition for "Medical Support Gas" one of the examples they list are air-driven booms. That gives weight to the argument that booms should be driven by nitrogen or instrument air as per NFPA 99.

The term "shall" is used when the language is mandatory. So 5.1.13.1.2 says "shall be permitted" so I'm just going to say I don't know, people should just do whatever makes them happy with regards to boom brakes.

I would only use brakes that are driven by electricity because finding nitrogen leaks often involves a stupid amount of effort to meet 5.1.14.2.3.2 requirement. It just so happens that I don't have any plans to purchase any booms in the near future so my opinion on the matter is pretty useless